Method of repelling insects employing



United States Patent 3,148,111 IVIETHOD 0F REPEILING INSECTS EMPLOYING NTTROPHENYL SULFIDES Edward J. Soboczenski, Chadds Ford, Pa., assignor to E. I. du Pont de Nemours and Company, Wilmington, DeL, a corporation of Delaware No Drawing. Filed Aug. 1, 1962, Ser. No. 213,373 3 Claims. (Cl. 167-30) This invention relates to insect repellents. More specifically, it refers to the use of alkyl o-nitrophenyl sulfides and compositions containing them as insect repellents.

The search continues for improved insect repellents. According to this invention it is quite surprisingly discovered that methyl and ethyl o-nitrophenyl sulfides are effective insect repellents when used in the manner of this invention. Most repellents are effective against only one or two insect species. However, the repellent of this invention is effective against many insect species.

The active compounds of this invention have the structural formula:

wherein R is methyl or ethyl.

Use.The alkyl o-nitrophenyl sulfides used in this invention are excellent insect repellents. Insects repelled include such insects as German cockroach and other roach species, confused fiour beetle, black carpet beetle, house fly and Mexican bean beetle. The compounds of this invention, when used in compositions containing liquid diluents or solid particulate diluents, protect treated surfaces such as industrial equipment and backs of cattle from being attacked by the described insects.

Composition-Insect repellent compositions of this invention will ordinarily comprise at least one compound of formula 1 with one or more surfactants, or with a finely divided solid diluent or a liquid diluent.

The surface-active agents used in this invention to assist dispersion of the composition can be a dispersant, wetting agent or emulsifying agent. The surface-active agent or surfactant can include such anionic, cationic and non-ionic agents as have heretofore been generally employed in pest control compositions of similar type. Suitable surfaceactive agents are set out, for example, in Searle U.S. Patent 2,426,417; Todd U.S. Patent 2,655,447; I ones U.S. Patent 2,412,510; or Lenher US. Patent 2,139,276. A detailed list of such agents is set forth in Detergents and EmulsifiersUp to Date (1962) by John W. McCutcheon, Inc., and Bulletin E607 of the Bureau of Entomology and Plant Quarantine of the U.S. Department of Agriculture.

Suitable surface-active agents for use in compositions of the present invention are: polyethylene glycol fatty esters and fatty alkylol amide condensates, alkyl aryl sulfonates, fatty alcohol sulfates, dialkyl esters of sodium sulfosuccinate, fatty acid esters of sodium isethionate, polyoxyethylene thioether and long chain quaternary ammonium chloride.

Among the more preferred surfactants are the anionic and non-ionic type. Among the anionic surface-active agents, preferred ones are alkali metal or amine salts of alkyl benzene sulfonic acids such as dodecylbenzene sulfonic acid, sodium lauryl sulfate, alkyl naphthalene sulfonates, sodium N-methyl-N-oleoyltaurate, oleic acid ester of sodium isethionate, dioctyl sodium sulfosuccinate, sodium dodecyldiphenoloxide disulfonate. Among the nonionic compounds, preferred members are alkyl phenoxy poly (ethyleneoxy) ethanols such as nonyl phenol ad 3,148,111 Patented Sept. 8, 1964 duets with ethylene oxide; trimethyl nonyl polyethylene glycol ethers, polyethylene oxide adducts of fatty and rosin acids, long chain alkyl mercaptan adducts with ethylene oxide. Surface-active dispersing agents such as sodium lignin sulfoantes, low viscosity methyl cellulose, polymerized sodium salts of alkyl naphthalene sulfonic acids are also suitable in the insect repellent compositions of this invention.

In general, less than 10% by weight of surfactants will be used in compositions of this invention and ordinarily the amount of surfactant will range from 1-5% but may even be less than 1% by weight.

The insect repellent compositions of this invention can contain, with or without surfactant, finely divided inert diluents such as talcs, natural clays, including kaolinites, and attapulgite, pyrophyllite, diatomaceous earths, synthetic fine silicas, calcium silicate, carbonates, calcium phosphates, sulfur, lime, and such flours as walnut shell, wheat, redwood, soybean and cottonseed.

The amount of finely divided inert solid diluent can vary widely and ordinarily will range from 10 to 99% by weight of the insect repellent composition.

Particle size of the inert solid diluent can vary considerably but will ordinarily be somewhat under 50 microns in the finished formulation.

The repellent compositions of this invention can also be applied as solutions which are sprayed, brushed or wiped on the surface from which insects are to be repelled. For this method of application, the repellent materials are mixed with a diluent such as, for example, naphtha, kerosene, toluene, xylene, nitrobenzene, chlorobenzene, cyclohexanone, acetone, methylisobutyl ketone or a mixture of high boiling isoparaffinic hydrocarbons. The preferred isoparafiinic hydrocarbon fraction has a boiling point in the range of 260 F. to 800 F. and is commonly known as Soltrol. Other suitable solvents include chlorinated aliphatic hydrocarbons, high boiling ethers, Cellosolves, Carbitols and the like.

The repellent compositions of this invention can also be applied in the form of an aqueous emulsion. The active ingredients can be dissolved in a substantially water insoluble solvent such as one of the aforementioned solvents and the resulting solution emulsified with water. Any one of the emulsifying or wetting agents mentioned above can be employed.

The concentration of active ingredient in the solvent, with or without surfactant to make the mixture emulsifiable, can range from dilute solutions, upwards of 1% to more concentrated solutions containing 30% and even 40% active ingredient. While the former are suitable for direct application, solutions having a strength greater than about 20% are particularly suitable as concentrates which are diluted with solvents, or are emulsified in water, at the time of application. For certain applications concentrates containing more than 40% of the repellent compound may be useful. In such compositions the active ingredient may range to the rest being one of the above mentioned solvents, possibly mixed with a surfactant. These concentrates, While solids under normal conditions of temperature, emulsify or dissolve rapidly and easily to give useful, more dilute sprays.

The compositions of this invention can also contain, if desired, an odorant such as perfume. Additionally, compositions can contain other known insect repellents such as succinic acid-di-n-butyl-ester or m-toluic acid-di-ethylamide.

Applicatiom-The compositions of this invention can be sprayed, brushed or spread directly on the animal or inanimate surface to be protected. The exact amount of active ingredients will vary according to the type of surface to be protected, the time of the year and like variables. In general, however, surfaces to be protected will be sprayed or brushed so that a thin film of active agent is established.

In addition to the examples described above, the following examples are provided to more clearly describe the invention. It is understood that all percents are weight unless otherwise indicated.

Example 1 Percent Methyl o-nitrophenyl sulfide 25.0 Mixed polyoxyethylene ethers and oil soluble petroleum sulfonates 6.0 Xylene 69.0

The above emulsifiable oil is prepared by simple mixing of the components to yield a clear solution. This composition is diluted with deodorized kerosene (Deobase) to a concentration of 1% active and applied by means of a compressed air sprayer to the basement walls and behind the counters of a restaurant. Cockroaches are repelled from the treated areas for an extended period.

Example 2 Percent Methyl o-nitrophenyl sulfide 50.0 Alkyl naphthalene sulfonic acid, Na salt 1.5 Partially desulfonated sodium lignin sultonate 1.0

Synthetic fine silica 47.5

Methyl o-nitrophenyl sulfide 3.0 Diatomaceous silica 2.0 Micaceous talc 95.0

The active and minor diluent are first mixed and micropulverized, then blended with the major diluent to give a dust composition. The dust is applied to the face and backs of cattle to repel fiies and other annoying insect species.

4 Example 4 The composition of Example 1 is applied to fiber board packaging material by conventional coating equipment. The resultant fiber board is used for fabricating packing cases for cartons of dry cereal. Stored-product insects are repelled from the treated cases and the contents thereby protected from insect damage.

Example 5 The under surface of a wool rug is sprayed with the composition of Example 2 at the rate of 0.2 gram active per square foot. When laid in a house in the conventional manner, extended protection of the rug from carpet beetle attack is provided by the repellency of this methyl o-nitrophenyl sulfide treatment.

Examples 6-10 Ethyl o-nitrophenyl sulfide is substituted for methyl o-nitrophenyl sulfide in each of the Examples 1 to 5 in like amount by weight. The composition is mixed in the same manner and when applied in like manner gives like results.

The invention claimed is:

1. Method of imparting insect repellency to the surface of animals and inanimate objects which comprises applying to said surface in an amount sufiicient to repel insects a compound of the formula:

wherein R is alkyl of less than 3 carbon atoms.

2. Method of imparting insect repellency to the surface of animals and inanimate objects which comprises applying to said surface in an amount sufiicient to repel insects methyl o-nitrophenyl sulfide.

3. Method of imparting insect repellency to the surface of animals and inanimate objects which comprises applying to said surface in an amount sufiicient to repel insects ethyl o-nitrophenyl sulfide.

References Cited in the tile of this patent King: US. Dept. Agr. Handbook No. 69 (May 1954), page 319. 

1. METHOD OF IMPARTING INSECT REPELLENCY TO THE SURFACE OF ANIMALS AND INANIMATE OBJECTS WHICH COMPRISES APPLYING TO SAID SURFACE IN AN AMOUNT SUFFICIENT TO REPEL INSECTS A COMPOUND OF THE FORMULA: 